The research activities in
"Bio-functional Materials and Tissue engineering Laboratory (BMTL)" are dedicated to:
(1) Defining the specialized characteristics of the cellular and extracellular microenvironment in which specific cells (stem cells, or tissue-specific cells) reside in vivo,
(2) Using multi-disciplinary approaches in chemistry, material science and engineering, cell/molecular biology, bio-imaging, and medical science to develop artificial constructs mimicking native environment to understand and control the behavior of cells,
(3) Ultimately engineering functional regenerative units that can replace or repair damaged tissue.
Given that, our ongoing research is focused on:
(1) Surface modification of biomaterials
Bio-inspired surface coating of biomaterials
The appropriate cellular environment regulates cell survival including adhesion, spreading, proliferation and differentiation activities. During the development of a tissue engineering strategy, biodegradable poly(α-hydroxy)esters have been widely used as scaffolds due to their biocompatibilities and good mechanical properties. Despite these excellent characteristics, active control of cellular behaviors has been limited due to the absence of cellular interactivity. We are developing surface modification techniques of biodegradable polymers with peptides and/or proteins to modulate specific cell function for tissue engineering applications.
Controlled release of growth factor for tissue regeneration
The formation of robust blood vessel is required for regeneration of ischemic myocardium or hind limb as well as for survival of transplanted tissues of large size. In particular, the interactions of ECM molecules with growth factors such as vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are important in the formation of blood vessels. We hypothesized that sustained release of angiogenic growth factor via similar interactions with native ECM proved by modified nanofibers will generate vascularized environment for many applications, regeneration of damaged bone and cardiac tissue.
(2) Tissue engineering
Bone tissue engineering
The implantation of engineered scaffolds is one of several potential strategies to facilitate the regeneration of damaged bone tissue caused by trauma or genetic diseases. Therefore, extensive efforts have been made to develop artificial bone replacement scaffolds based on bioceramics, polymers, metallic materials, and their composites. In addition, delivery of appropriate cell population with biomimetic scaffold has been proposed to improve bone regeneration efficacy. We hypothesized that composite nanofibers containing biodegradable polymers and bioactive inorganics with combination of bone forming cells and endothelial cells for well-vascularization may be ideal system be regenerate damaged bone. We are currently working on development of new materials and novel strategy for bone tissue engineering.
Electrically conductive nanofibers for tissue engineering
Electrical signals are critical physiological stimuli that control the adhesion and differentiation of certain cell types. Early work to culture cells on biomaterials capable of providing electrical cues investigated conducting polymers such as polypyrrole (PPy) and polyaniline (PANi). We have developed composite fibers consisting of electrically conductive polymers and poly(l-lactide-co-ε-caprolactone) (PLCL), thereby generating electrically conductive composite nanofibers. We envisioned a composite nanofiber that could be utilized as a temporary substrate to stimulate tissue formation controlled by electrochemical signals as well as continuous mechanical stimulation under normal regeneration processes, i.e. muscular or neural tissue. We are currently engineering the composite nanofibers for control of muscle cell differentiation and neurol cell outgrowth.